Cirrus down Gundaroo, 06/10/23
Perhaps severe icing, stall and spin, tangling the chute and damaging comms antennas.
Please everyone: Don’t feed the beast with speculation about sudden incapacitation and ‘evil thought’, especially when it’s a nonsensical explanation just on the cockpit ergonomics of a Cirrus and what actually happens if you point most any ‘light’ aircraft straight at the ground. It’s an awful enough outcome without the AvMeds of the world milking it before the smoke’s dissipated. The pilot’s medical history and domestic circumstances will be revealed, eventually.
Please everyone: Don’t feed the beast with speculation about sudden incapacitation and ‘evil thought’, especially when it’s a nonsensical explanation just on the cockpit ergonomics of a Cirrus and what actually happens if you point most any ‘light’ aircraft straight at the ground. It’s an awful enough outcome without the AvMeds of the world milking it before the smoke’s dissipated. The pilot’s medical history and domestic circumstances will be revealed, eventually.
I have known fit and able people suffer a medical emergency and die, totally unexpected. One was mid 40s, training for the Tour de Flanders bicycle course, supremely fit. Went out one evening to ride his bike to his parents, got there, dismounted - collapsed, dead. We pilots aren't immune to such issues, I'm afraid.
Yes I am a pilot, cncpc. And, nearly four decades in, I'm getting very tired of the mixture of amateurs, accident ghouls, media trolls and - worst of all - self-interested aircraft manufacturers and maintainers who are so keen to blame the pilot for accidents. And pilot incapacitation feeds straight into Avmed's justification.
You, of course, are just a disinterested observer, with no direct or indirect financial interest in Cirrus or BRS, or in Avmed issues, who's just appeared for purely altruistic reasons to nudge pilot incapacitation as the cause. Aren't you.
You, of course, are just a disinterested observer, with no direct or indirect financial interest in Cirrus or BRS, or in Avmed issues, who's just appeared for purely altruistic reasons to nudge pilot incapacitation as the cause. Aren't you.
have no financial interests in any of the above things you mentioned but I still believe the issue was due in part to pilot incapacitation which led to a stall during icing - let's face it, he had climbed to 9500 feet on his way to 10.000 ft - which appeared to be his preferred level - the freezing level was already forecast for between 5000 and 8000feet; the forecast also described broken SC & CU clouds between 5000 and 10000 feet.
He wasn't flying on autopilot, of that we can be sure because of the heading variations and autopilots fitted to the Cirrus require a roll mode to be activated for pitch mode to be used. Therefore the plane had been trimmed for a cruise climb. My belief is he had a medical issue, the aircraft climbed through heavy clouds, picked up ice; because the pilot didn't respond, the aircraft stalled.
Having owned a Cirrus, I know how strong they are, I've not heard of an SR20 / SR22 aircraft coming apart whilst flying below Vne. His issues started whilst at low speed. Sufficient CAPS systems have been deployed, if they could have mis-deployed. tangled with the Comms antennas, we would have heard about it. Let's say his tail broke off, that wouldn't stop his ability to pull the chute, nor to communicate.
As indicated, my current aircraft is also equipped with BRS and if I was at 9500 feet and had a structural failure, I would pull the lever and then contact ATC to let them know where I am heading. If I had a mechanical failure - engine failure, for example, I have enough time from 9500 feet to trouble shoot the issue whilst checking I keep the airspeed below Vpd and above my self imposed deployment hard-deck.
Occam's Razor tells us that to resolve a conundrum, look for the solution of a problem with the minimum number of conditions.
So, to conclude: Aircraft was climbing without an autopilot active. The plane's airspeed started to decrease. The aircraft had already started to drop like a stone before reaching stall speed. The pilot did not respond to any of the issues, didn't make any calls. Didn't pull the chute.
Why? because he couldn't..... Just my 2c worth.....
The following users liked this post:
I'm with LB on the issue of blaming pilots when there is no evidence of it. The A36 example above makes little sense to say it was on autopilot, but then descended at 5000fpm. When quite a few known cases of pilot incapacitation tend to have the aircraft continue to fly until fuel exhaustion or the pilot wakes up and regains control. Not enter a sudden plunge to doom.
The stec autopilot in the early Cirrus doesn’t have a IAS hold as it uses vertical speed. Speed could decay away as the altitude increases, which it doesn’t really, so it’s performing well with 315 hp.
So with the ADSB feed being ground speed, I’m assuming the speed “blip” early on of close to 20 knots is a 20 know westerly as he turns briefly onto “crosswind” on the departure track.
The profile appears to be a consistent climb to max altitude at what is probably the best rate you could get out it is, on the way to the pilots alleged preferred 10,000ft. The airspeed is low though… it’s a lowish speed with a high climbing angle into thinning air. If there was in fact ice building up, it’s building up on the underside of the wing, MU2 style. Add this to the laminar flow Cirrus wing at high angle of attack and when the wing drops, it will drop hard, potentially inverted.
We all know that a Cirrus isn’t getting out of a spin with no chute and I wouldn’t be at all surprised if nobody was able to pull it.
Of course this would all be pending icing levels and cloud at the time….
On the flip side an incapacitated pilot scenario with 10k in the STEC in non-icing conditions doesn’t immediately result in this scenario either. For a passenger to turn off the auto pilot they need to press any hold the button on the controls for a couple of seconds and hear the loud beeps first. Seems somewhat unlikely.
The main standout for me is that the speed seems a little low from the start which reduces margins, especially when up high and if icing was present, or any other scenario that could cause a wing drop.
So with the ADSB feed being ground speed, I’m assuming the speed “blip” early on of close to 20 knots is a 20 know westerly as he turns briefly onto “crosswind” on the departure track.
The profile appears to be a consistent climb to max altitude at what is probably the best rate you could get out it is, on the way to the pilots alleged preferred 10,000ft. The airspeed is low though… it’s a lowish speed with a high climbing angle into thinning air. If there was in fact ice building up, it’s building up on the underside of the wing, MU2 style. Add this to the laminar flow Cirrus wing at high angle of attack and when the wing drops, it will drop hard, potentially inverted.
We all know that a Cirrus isn’t getting out of a spin with no chute and I wouldn’t be at all surprised if nobody was able to pull it.
Of course this would all be pending icing levels and cloud at the time….
On the flip side an incapacitated pilot scenario with 10k in the STEC in non-icing conditions doesn’t immediately result in this scenario either. For a passenger to turn off the auto pilot they need to press any hold the button on the controls for a couple of seconds and hear the loud beeps first. Seems somewhat unlikely.
The main standout for me is that the speed seems a little low from the start which reduces margins, especially when up high and if icing was present, or any other scenario that could cause a wing drop.
The stec autopilot in the early Cirrus doesn’t have a IAS hold as it uses vertical speed. Speed could decay away as the altitude increases, which it doesn’t really, so it’s performing well with 315 hp.
So with the ADSB feed being ground speed, I’m assuming the speed “blip” early on of close to 20 knots is a 20 know westerly as he turns briefly onto “crosswind” on the departure track.
The profile appears to be a consistent climb to max altitude at what is probably the best rate you could get out it is, on the way to the pilots alleged preferred 10,000ft. The airspeed is low though… it’s a lowish speed with a high climbing angle into thinning air. If there was in fact ice building up, it’s building up on the underside of the wing, MU2 style. Add this to the laminar flow Cirrus wing at high angle of attack and when the wing drops, it will drop hard, potentially inverted.
We all know that a Cirrus isn’t getting out of a spin with no chute and I wouldn’t be at all surprised if nobody was able to pull it.
Of course this would all be pending icing levels and cloud at the time….
So with the ADSB feed being ground speed, I’m assuming the speed “blip” early on of close to 20 knots is a 20 know westerly as he turns briefly onto “crosswind” on the departure track.
The profile appears to be a consistent climb to max altitude at what is probably the best rate you could get out it is, on the way to the pilots alleged preferred 10,000ft. The airspeed is low though… it’s a lowish speed with a high climbing angle into thinning air. If there was in fact ice building up, it’s building up on the underside of the wing, MU2 style. Add this to the laminar flow Cirrus wing at high angle of attack and when the wing drops, it will drop hard, potentially inverted.
We all know that a Cirrus isn’t getting out of a spin with no chute and I wouldn’t be at all surprised if nobody was able to pull it.
Of course this would all be pending icing levels and cloud at the time….
Just thinking out loud..
(Keeping in mind that the wings and tail plane appeared to be intact in the aftermath and assuming the elevator controls are still firmly attached)
The aircraft was also cleared direct to CULIN, which initially it appeared to do. Then the lateral tracking started to ‘wander.’ Like HDG mode was engaged or being hand flown.
I know we all know what a spin looks like, but thinking about ADSB data feeds and update times… hard to know what it would pick up in terms of heading during such an event. The graphs draw mean lines. You need to see the data in dot form.
The following users liked this post:
There remained an appreciable horizontal velocity component up until the highest descent rate. Both the speeds from my attachments and the other post with FR24 data is GPS derived ground speed. Lack of forward movement simply indicates the velocity vector might be pointing more downward than forward, corroborated by the peak geometric descent rate at 03:48:49 UTC of over -17,000fpm (~167 kts) and 84 kts forward speed at the same time, for a total velocity vector of (84^2 + 167^2)^0.5 = 187 kts. After that point the forward velocity reduced abruptly to around 18 kts on average until end of transmission. The vertical rate reduced to about -12,000 fpm (~118kts) for the last 15 seconds.
There's a change in geometric rate fluctuations from about 5 minutes before the event, perhaps that's when they climbed into a turbulent layer/cloud or that's where some difficulties started to evolve (pretty much from after where the data gap is in the plots). The data gap itself is from an interruption in the data feed, not from ceased transmissions by the aircraft.
There's a change in geometric rate fluctuations from about 5 minutes before the event, perhaps that's when they climbed into a turbulent layer/cloud or that's where some difficulties started to evolve (pretty much from after where the data gap is in the plots). The data gap itself is from an interruption in the data feed, not from ceased transmissions by the aircraft.
The following 2 users liked this post by physicus:
Thank you so much. I didn’t know how to extract the dots from the feed. Much easier to read that now!
I'm now thinking stall spin is definitely an option. I just looked at the recent Seminole accident in the US, which was most definitely a spin as it was caught on camera. The flight aware profile is very similar. The chute failure option is still there as well as structural failure. The fluctuations in speed look like passing through the clouds that are apparent in the background of the photos, smallish broken cumulus, will kick a light plane around a little bit as you enter and leave, it will also cause the vertical speed to fluctuate with the up/down drafts. The heading variations may have been the pilot picking small holes close to track initially, then punching in as it thickened. Unless there's some eyewitness accounts pop up, I'm sure this will go down as multiple possibilities as I doubt there will be much information gained from the wreckage, that is unless parts are found away from the main site.
PS, even though I'm opening up to the stall/spin, the speeds involved are still making me think otherwise.
PS, even though I'm opening up to the stall/spin, the speeds involved are still making me think otherwise.
Last edited by 43Inches; 7th Oct 2023 at 22:17.
Forecast at the time was BKN CU/SC 5000' to 10000', Freezing layer 5000' and SNSH (snow showers) above 5000'. I know there can be difference between forecast and actual, but I still think it was icing.
And enter, stage left, Lookleft whose pathological obsession with disagreeing with everything I post – whatever the subject - is such that, not only has she searched far and wide to find an example, she disagrees with something I did not say:
I did not say it is “impossible” for sudden pilot incapacitation to result in an aircraft plummeting to the ground.
It is “possible” that a meteorite struck the aircraft, resulting in it plummeting to the ground.
As 43” observed:
Here’s an example where an aircraft ‘landed itself’ with the pilot unconscious, and the pilot survived:
So no doubt there are examples of aircraft plummeting to the ground due to pilot incapacitation, but there are many more examples where that doesn't happen. And there is a particular characteristic of the Cirrus that is relevant here.
Thank you for your very considered and informed post, FMJ.
Rest assured: I understand that all sorts of ostensibly healthy people collapse and die, unexpectedly, of some undetected affliction. The only pilots I know who’ve died unexpectedly at the controls were the holders of Class 1 medical certificates (thus exposing the expensive Avmed façade for what it is).
With your first-hand experience in the ergonomics of a Cirrus cockpit, could you please expand on how a pilot of a Cirrus "slumps across the controls, locking them"? Exactly what bits of the pilot’s body end up where, and how does that happen despite the shoulder harness?
Have you had a look at the CAPS Event database to which I posted a link earlier in the thread? There are numerous events – and of course numerous events not involving Cirrus aircraft – where no mayday is transmitted by a conscious pilot who’s busy on higher priorities. Did you note the events of ‘unilateral’ deployment attributed to static electricity?
I do think you might have misinterpreted what some of the reported parameters mean as to airspeed versus rate of climb/descent. My theory is based on discussions I’ve had with people who understand the numbers and the Cirrus – and some comments made here – which suggest a near-vertical descent but with some kind of unusual drag … like an aircraft with parachute lines tangled around the fuselage and tailplane and the parachute barely able to inflate. My comment about the comms antenna was the result of the physical characteristics of the Comm 1 antenna compared to other antennae in that scenario. But of course we don’t know if the pilot even tried to transmit a mayday.
Earlier in this thread reference was made – correctly - to the probability that the aircraft “would have just had it’s second 10 year chute re-pack completed”. As soon I read that, I consider the risk of maintenance induced failure. The flight I fear most is the first one after my aircraft has been the subject of mandated meddling. There have been many creative attempts made on my life by LAMEs over the years – not deliberate I hope. But the fact is: people make mistakes. It will therefore be important for the ATSB to investigate the maintenance history of the CAPS in particular.
Hopefully the ATSB folk will be able to ascertain at least whether the CAPS was deployed or not. Given the location, I would be surprised if there were no eye witnesses of even a couple of seconds of the descent. You will see, from the events database, that in one tragedy arising from icing the empty parachute was seen descending minutes after the aircraft impacted the ground. If this aircraft’s parachute is found intact some distance from the impact site, that would be a ‘lay down misère’ on a number issues.
Not as impossible as you might think.
It is “possible” that a meteorite struck the aircraft, resulting in it plummeting to the ground.
As 43” observed:
[Q]uite a few known cases of pilot incapacitation tend to have the aircraft continue to fly until fuel exhaustion or the pilot wakes up and regains control. Not enter a sudden plunge to doom.
So no doubt there are examples of aircraft plummeting to the ground due to pilot incapacitation, but there are many more examples where that doesn't happen. And there is a particular characteristic of the Cirrus that is relevant here.
Thank you for your very considered and informed post, FMJ.
Rest assured: I understand that all sorts of ostensibly healthy people collapse and die, unexpectedly, of some undetected affliction. The only pilots I know who’ve died unexpectedly at the controls were the holders of Class 1 medical certificates (thus exposing the expensive Avmed façade for what it is).
With your first-hand experience in the ergonomics of a Cirrus cockpit, could you please expand on how a pilot of a Cirrus "slumps across the controls, locking them"? Exactly what bits of the pilot’s body end up where, and how does that happen despite the shoulder harness?
Have you had a look at the CAPS Event database to which I posted a link earlier in the thread? There are numerous events – and of course numerous events not involving Cirrus aircraft – where no mayday is transmitted by a conscious pilot who’s busy on higher priorities. Did you note the events of ‘unilateral’ deployment attributed to static electricity?
I do think you might have misinterpreted what some of the reported parameters mean as to airspeed versus rate of climb/descent. My theory is based on discussions I’ve had with people who understand the numbers and the Cirrus – and some comments made here – which suggest a near-vertical descent but with some kind of unusual drag … like an aircraft with parachute lines tangled around the fuselage and tailplane and the parachute barely able to inflate. My comment about the comms antenna was the result of the physical characteristics of the Comm 1 antenna compared to other antennae in that scenario. But of course we don’t know if the pilot even tried to transmit a mayday.
Earlier in this thread reference was made – correctly - to the probability that the aircraft “would have just had it’s second 10 year chute re-pack completed”. As soon I read that, I consider the risk of maintenance induced failure. The flight I fear most is the first one after my aircraft has been the subject of mandated meddling. There have been many creative attempts made on my life by LAMEs over the years – not deliberate I hope. But the fact is: people make mistakes. It will therefore be important for the ATSB to investigate the maintenance history of the CAPS in particular.
Hopefully the ATSB folk will be able to ascertain at least whether the CAPS was deployed or not. Given the location, I would be surprised if there were no eye witnesses of even a couple of seconds of the descent. You will see, from the events database, that in one tragedy arising from icing the empty parachute was seen descending minutes after the aircraft impacted the ground. If this aircraft’s parachute is found intact some distance from the impact site, that would be a ‘lay down misère’ on a number issues.
Last edited by Lead Balloon; 8th Oct 2023 at 00:47.
The following users liked this post:
Yes I am a pilot, cncpc. And, nearly four decades in, I'm getting very tired of the mixture of amateurs, accident ghouls, media trolls and - worst of all - self-interested aircraft manufacturers and maintainers who are so keen to blame the pilot for accidents. And pilot incapacitation feeds straight into Avmed's justification.
You, of course, are just a disinterested observer, with no direct or indirect financial interest in Cirrus or BRS, or in Avmed issues, who's just appeared for purely altruistic reasons to nudge pilot incapacitation as the cause. Aren't you.
You, of course, are just a disinterested observer, with no direct or indirect financial interest in Cirrus or BRS, or in Avmed issues, who's just appeared for purely altruistic reasons to nudge pilot incapacitation as the cause. Aren't you.
Lead, the grip is getting a bit tight there mate. Don't cut the blood supply to it 
Truly a miserable accident, 3 kids.
Odd to see some pprune commentators here that appear to have locked in a cause, I like people with conviction, generally, but from the grainy photos and basic telemetry on your computer screen is likely the wrong place to form such a conviction. If you wish to excel in aviation the quicker you drop the locked in assumption proclivity the better.
Makes me think we need to keep moving forward with retrievable data loggers in GA types, particularly the composite aircraft as they are typically newer designs able to incorporate at manufacture and if there is a post crash fire there is not much left to work with from composite aircraft.
Nothing much fits as to the cause, pilot incapacitation, possible, but unlikely profile for such an event, I sort of imagine the kid in the front seat would not likely dive the aircraft against the trim forces and if grandpa was incapacitated you would think the kid in the front seat could keep it level-ish. Structural failure or control failure, possible, but pretty unlikely, icing possible but doesn't match the profile that well either. All of these move up toward probable if it can be shown that the CAPS deployment had been attempted. But no CAPS and no radio call???
I haven't read every post but I wondered why in flight electrical fire hasn't been raised.
I am not Cirrus endorsed but I would imagine that in the event of detecting electrical smoke that turning off nearly everything electrical (including avionics) happens pretty quickly in the flow. It may not be that the aircraft itself had an electrical fire, with 3 kids on board for a 2 night stay away with family the likelihood of Lithium powered devices/toys is likely. A stowed item that thermal runaways may not be able to be differentiated from an aircraft electrical fire. What drill could have been adopted, instinct and likely the QRH reference might be...isolate/turn off master switch and adopt max RoD. Perhaps not a priority to talk to centre in SPIFR with an onboard electrical fire, nice if you can, but maybe you don't. (post edit, apparently the data output we are seeing is from the txpr so indicates avionics on if that's the case).
Then a clearing has to be found to put it down, how much smoke in the cockpit and how toxic is it. A witness (for what it's worth) reported (media report) the aircraft travelling at tree top height before spiraling into the ground followed by a large explosion. A fire could fit but pretty rare event too.
Certainly nothing clear cut about this from where we're sitting except for the miserableness of it all.
Odd to see some pprune commentators here that appear to have locked in a cause, I like people with conviction, generally, but from the grainy photos and basic telemetry on your computer screen is likely the wrong place to form such a conviction. If you wish to excel in aviation the quicker you drop the locked in assumption proclivity the better.
Makes me think we need to keep moving forward with retrievable data loggers in GA types, particularly the composite aircraft as they are typically newer designs able to incorporate at manufacture and if there is a post crash fire there is not much left to work with from composite aircraft.
Nothing much fits as to the cause, pilot incapacitation, possible, but unlikely profile for such an event, I sort of imagine the kid in the front seat would not likely dive the aircraft against the trim forces and if grandpa was incapacitated you would think the kid in the front seat could keep it level-ish. Structural failure or control failure, possible, but pretty unlikely, icing possible but doesn't match the profile that well either. All of these move up toward probable if it can be shown that the CAPS deployment had been attempted. But no CAPS and no radio call???
I haven't read every post but I wondered why in flight electrical fire hasn't been raised.
I am not Cirrus endorsed but I would imagine that in the event of detecting electrical smoke that turning off nearly everything electrical (including avionics) happens pretty quickly in the flow. It may not be that the aircraft itself had an electrical fire, with 3 kids on board for a 2 night stay away with family the likelihood of Lithium powered devices/toys is likely. A stowed item that thermal runaways may not be able to be differentiated from an aircraft electrical fire. What drill could have been adopted, instinct and likely the QRH reference might be...isolate/turn off master switch and adopt max RoD. Perhaps not a priority to talk to centre in SPIFR with an onboard electrical fire, nice if you can, but maybe you don't. (post edit, apparently the data output we are seeing is from the txpr so indicates avionics on if that's the case).
Then a clearing has to be found to put it down, how much smoke in the cockpit and how toxic is it. A witness (for what it's worth) reported (media report) the aircraft travelling at tree top height before spiraling into the ground followed by a large explosion. A fire could fit but pretty rare event too.
Certainly nothing clear cut about this from where we're sitting except for the miserableness of it all.
Last edited by Obidiah; 8th Oct 2023 at 00:41.
The following 2 users liked this post by Obidiah:
It's the profile matched with the speed and rate of descent that leaves many questions. An emergency descent at around 10 degrees nose down will reach VMO/VNE at idle power relatively quickly without some form of drag device, you will then have to raise the attitude to prevent busting structural speeds. That will generally net you in the region of 3000fpm. To dive vertically, but keep the speed at most 180kts, and decreasing despite the attitude, well that's just odd. Granted there will be some errors in the ADSB plots based on what is received, but even then the descent had to be very steep.
Does Cirrus have an internal investigation unit?
Could battery residue be found in the remains of that accident site ?
Could battery residue be found in the remains of that accident site ?
43" Yes likely right, it is a bit steep for an emergency descent. I have seen these profiles before a number of times. I hope for closure sake they are able to establish a cause.